A MBTA bus passenger got into a fight with a driver and spat on her. The driver retaliated by hitting the passenger over the head with a wooden block, according to the Suffolk County District Attorney's office.

Both driver and passenger were supposed to end up in court on Thursday, but the passenger never showed.

The Dec. 20 spat - literally - occurred when Homer Henderson, 52, of Roxbury, was a passenger on a Route 1 bus.

According to Assistant District Attorney Eric Anderson, Henderson fell asleep on the bus, then woke up and engaged in a conversation with driver Terri Felix, 40, of Brockton. The discussion escalated into an argument, which was filmed by another passenger. When the bus stopped, Henderson allegedly spat on Felix before getting off the bus.

Prosecutors say Felix got a wooden chock block, a block typically used as a tire stop, from a storage compartment, then followed Henderson down the street. She allegedly hit him on the head with the wooden block, knocking him down, then returned to the bus and called the transit police. Henderson, who was treated at Boston Medical Center, said he had a laceration to his mouth, a broken bone in his cheek and other injuries.

Felix was charged with assault and battery with a dangerous weapon in Boston Municipal Court and released on her own recognizance.

Henderson was also charged with assault and battery with a dangerous weapon. After he failed to appear in court on Thursday, a warrant was issued for his arrest.